Journal of Current Ophthalmology
Volume:29 Issue: 1, Mar 2017

To review current literature on the renin-angiotensin system (RAS)-mediated pathogenic mechanisms and therapeutic targets in ocular diseases.
A comprehensive literature survey was performed on PubMed, Scopus, and Google Scholar databases published from 1977 to 2016. The search terms were a RAS, angiotensin, angiotensin receptor, prorenin, pro (renin) receptor, angiotensin converting enzyme inhibitor, angiotensin receptor blocker associated with ocular disorders like cataract, glaucoma, diabetic retinopathy (DR), macular degeneration, and uveitis. Articles were reviewed on the basis of the association between ocular disorders and RAS and relevant articles were discussed.
The literature revealed that the individual RAS components including renin, angiotensins, angiotensin converting enzymes, and RAS receptors have been expressed in the specific ocular tissues like retina, choroid, and ciliary body. The activation of both circulatory and local RAS potentiate the various inflammatory and angiogenic signaling molecules, including vascular endothelial growth factor (VEGF), extracellular signal-regulated kinase, and advanced glycation end products (AGE) in the ocular tissues and leads to several blinding disorders like DR, glaucoma, and macular degeneration. The classical and newer RAS inhibitors have illustrated protective effects on blinding disorders, including DR, glaucoma, macular degeneration, uveitis, and cataract.
The RAS components are present in the extrarenal tissues including ocular tissue and have an imperative role in the ocular pathophysiology. The clinical studies are needed to show the role of therapeutic modalities targeting RAS in the treatment of different ocular disorders.

To provide efficacy and safety of surgery with Trabectome combined with phacoemulsification in primary open-angle glaucoma.
In this interventional case series, 30 consecutive eyes that have had combined phacoemulsification with Trabectome were included. The main outcome measures were change in intraocular pressure (IOP), glaucoma medication use, and the rate of complications.
Mean IOP was 18.25 ± 3.28 mmHg preoperatively which decreased to 13.50 ± 2.53 mmHg at 1 year. (P Combined phacoemulsification and Trabectome significantly lowered IOP and medication use, with early visual rehabilitation in the majority of patients.

To determine the repeatability of corneal thickness measurements with Scheimpflug (Pentacam) and slit scanning (Orbscan) imaging techniques in different grades of keratoconus.
This study was conducted as a cross-sectional research. Imaging with Orbscan and Pentacam was performed on patients with different grades of keratoconus. With each device, 3 measurements were taken at 10 min intervals. Repeatability indices in different grades of keratoconus were calculated for each device.
Seventy-four eyes of 42 keratoconus patients were enrolled. Repeatability index (RI) of central corneal thickness (CCT) measurements in keratoconus grade 1, 2, and 3, were 12.8, 9.9, and 24.2 with Pentacam, and 23.6, 26.3, and 59.3 with Orbscan, respectively. For the thinnest point, these figures were 9.6, 8.0, and 35.7 with Pentacam and 19.5, 16.6, and 26.8 with Orbscan, respectively. The 95% limit of agreement (LOA) between Pentacam and Orbscan in measuring CCT and thinnest point in grade 1 were
25.5e47.7 mic and
33.3e32.8 mic, respectively. These results for grade 2 were
9.8e50.6 mic and
26.2 43.7 mic, respectively. In grade 3, 95% LoA were
20e64.6 mic and
31.4e60.5 mic, respectively.
The results of this study showed that although repeated measurements of the CCT with Orbscan and Pentacam are strongly correlated, repeatability values of CCT measurements significantly decrease at more advanced grades of keratoconus. In all keratoconus grades, repeatability of CCT measurements was better with Pentacam than Orbscan. These findings indicate that corneal thickness readings have less validity in patients with advanced keratoconus.

Pterygium is a pathologic process with angiogenic and tumor cell like characteristics. Chemokine and chemokine receptors may contribute to the formation and growth of pterygia. The aim of this study was to assess the expression of stromal cell derived factor (SDF)-1, as an angiogenic chemokine, and its receptors, CXCR4 and CXCR7, gene transcripts in pterygia.
RNAwas extracted from tissue samples of 33 patients with primary pterygium and 35 volunteers with conjunctiva as the control group. Then the mRNA expression of SDF-1, CXCR4, and CXCR7 was assessed through quantitative Real Time PCR method using appropriate primers.
SDF-1 and both receptors transcripts had significantly higher expression in pterygia samples compared to the control group (P As SDF-1 and its receptors, CXCR4 and CXCR7, were up-regulated in pterygia, SDF-1/CXCR4/CXCR7 axis may contribute to pterygium formation which can be possibly restrained by down-regulating this signaling pathway.

To investigate the effect of omega-3 polyunsaturated fatty acid supplement on qualitative and quantitative subjective (ocular surface disease index [OSDI]) and objective (Schirmer''s test, tear break up time [TBUT], and tear osmolarity) dry eye indices after cataract surgery.
In this randomized clinical study, 61 eyes of 48 patients complaining of new onset dry eye symptoms after phacoemulsification were enrolled. Subjects were randomly allocated into two groups using urn randomization. Controls received conventional treatment. The treatment group received omega-3 dietary supplement in addition to conventional therapy.
There was no significant difference between the control and treatment groups in pre-treatment indices of Schirmer (3.50 ± 3.13 and 2.96 ± 3.39, respectively, P ¼ 0.582), TBUT (6.67 ± 1.36 and 4.87 ± 2.22, respectively, P ¼ 0.687), osmolarity (316.66 ± 8.50 and 315.4 ± 17.06, respectively, P ¼ 0.906), and OSDI (32.99 ± 19.03 and 35.32 ± 18.99, respectively, P ¼ 0.635). Mean pre-treatment OSDI in the control group was 32.99 ± 19.03, which improved significantly after treatment to 25.43 ± 14.49 (P ¼ 0.003). The mean pre-treatment OSDI in the treatment group was 35.32 ± 18.99 (range: 7.5e77.77), which improved significantly after treatment to 16.31 ± 13.72 (range: 2.77e47.22) (P Omega-3 dietary supplements have an additive effect on tear film indices of patients with dry eye syndrome after phacoemulsification.

To determine the distribution of anterior eye biometry indices, such as keratometry pachymetry, anterior chamber depth (ACD), pupil diameter, and corneal diameter, as measured by Orbscan instrument in a young Iranian population.
A cross-sectional study was conducted, and subjects were selected through multistage cluster sampling from the students of Mashhad University of Medical Sciences. Objective and subjective refraction were performed followed by Orbscan imaging.
A total of 1330 subjects were selected, 1121 of which participated in the study. After applying the exclusion criteria, the final analysis was performed on the data of 1051 subjects. The mean age of the participants was 26.1 ± 3.2 years (19e34 years old). The mean ± SD and 95% confidence interval (CI) of maximum keratometry, minimum keratometry, pupil diameter, corneal diameter, ACD, and central corneal thickness was 44.5 ± 1.7 (44.4e44.6), 43.1 ± 1.6 (43.0e43.2), 4.3 ± 0.9 (4.3e4.4), 11.7 ± 0.4 (11.7e11.7), 3.7 ± 0.3 (3.6e3.7), and 550.5 ± 35 (548.4e552.6), respectively. After adjusting for age and the mean spherical equivalent (MSE), maximum keratometry, minimum keratometry, central corneal thickness, and the thinnest pachymetry were statistically significantly higher in female subjects (P In this study, the distribution of Orbscan measurements for the anterior segment parameters was reported in a large sample of the young Iranian population. Age, gender, and refractive error may affect the orbscan measurements.

To evaluate the efficacy of botulinum toxin injection in the patients with type 1 Duane syndrome and identify the predictive factors for success.
Sixteen patients with esotropic type 1 Duane syndrome without history of ocular surgery were selected for this interventional case series. The botulinum toxin was injected in the medial rectus of all patients. Visual acuity, dry refraction, cyclo-refraction, ocular motility, and amount of deviation were measured. Complete success, partial success, and failure were defined as residual deviation/face turn less than 8 prism diopters (PD)/5
, 8-20 PD/5-15
, and equal or greater than 20 PD/15
, respectively.
Sixteen cases (6 males) were included in our study. The mean esotropia was 26.27 ± 8.35 (12-40 PD) which was reduced significantly to 13.5 ± 12.39 PD during 6 months follow-up (p Botulinum toxin could be an alternative treatment in Duane syndrome with appropriate case selection. FDT could be a predictive factor for response to botulinum toxin.

To evaluate the predictive factors for development of diplopia and extraocular muscle movement (EOM) limitations in the patients with isolated pure blow-out fracture.
One hundred thirty-two patients with isolated pure blow-out fracture were included. The diagnosis was done with computed tomography scan. Possible predictive factors were analyzed with logistic regression. The cases that underwent surgery were assigned in the surgical group, and other cases were assigned in the non-surgical group. Receiver operating characteristic (ROC) curve analysis was used in the surgical group to evaluate the power of time interval from trauma to the surgery to predict persistence of 6 months postoperative diplopia and EOM limitation.
At the first visit, 45 of 60 cases (75%) in the surgical group and 15 of 72 cases 20.8%) in the nonsurgical group had diplopia. After 6 months follow-up, 7 cases (11.7%) in the surgical group and 1 case (1.4%) in the nonsurgical group had persistent diplopia. Type of fracture was significantly associated with first visit diplopia (P ¼ 0.01) and EOM limitations (P ¼ 0.06). In the surgical group, type of fracture (P ¼ 0.02 for both) and time interval from trauma to the surgery (P ¼ 0.006 and 0.004, respectively) were significantly associated with 1 month diplopia and EOM limitations. Only time interval from trauma to the surgery (P ¼ 0.04) was significantly associated with 3 months EOM limitation. In the ROC curve analysis, if the surgery was done before 4.5 (sensitivity ¼ 87.5% and specificity ¼ 61.3%) and 7.5 (sensitivity ¼ 87.5% and specificity ¼ 66.9%) days, risk of 6 months postoperative diplopia and EOM limitation was reduced, respectively.
In the early postoperative period, a higher rate of diplopia was observed in the patients with combined inferior and medial wall fractures and longer time intervals from trauma to the surgery. The best time for blow out fracture surgery was within 4.5 days after the trauma.

To evaluate the results of conjunctival culture in fellow eyes of patients with unilateral nasolacrimal duct obstruction (NLDO) and its changes after successful dacryocystorhinostomy (DCR) surgery.
In this prospective study, 71 adult patients with unilateral NLDO and 41 age and sex-matched controls without NLDO were evaluated. The patients were divided into 2 groups based on clinical examination; group A with purulent regurgitation and group B without purulent regurgitation. They all underwent DCR. Before DCR surgery, microbiologic specimens were taken bilaterally from the conjunctiva of both eyes. Postoperative conjunctival sampling was continued weekly until the culture became negative or the colony count reached to the range of the control group.
There were 38 and 33 patients in groups A and B, respectively. Silicone tube was inserted for 17 patients (23.9%). The culture was positive for bacterial growth in 56 fellow eyes (79%). The conjunctival culture in the control group was positive in 17 eyes (41.4%). The mean count of colonies in a sample unit was 624.73 ± 2412.31, 195.75 ± 407.56, and 9.5 ± 1.5 for group A, group B, and controls, respectively. The mean time of normalization of specimens was 1.43 ± 0.69 weeks (range 1e4). Higher colony count at baseline and presence of silicone tube in infected eye were significantly associated with longer normalization time for fellow eye (P This study suggests that after successful DCR surgery, a waiting period of 4 weeks is needed for conjunctival bacterial cultures to become negative or reach the level of the normal eyes, in the fellow eyes of patients with unilateral NLDO.

To describe a case of choroidal neovascularization (CNV) following photorefractive keratectomy (PRK) to correct myopia.
We performed PRK in both eyes of a 20-year-old girl to correct myopia. Refractive error was
4.75
2.25  5 in the right eye and
5.00
1.25  180 in the left eye. Metamorphopsia was noticed by the patient in the right eye one month after the surgical procedure. The patient was referred 3 months later when visual loss happened.
Fluorescein angiography and Optical Coherence Tomography (OCT) were performed which were compatible with CNV. After three monthly intravitreal bevacizumab injections, sub-retinal hemorrhage and intraretinal fluid resolved, but subretinal scar remained without any visual acuity improvement.
It seems that CNV may occur after PRK in myopic eyes. Also, refractive surgeons should consider CNV development in cases with visual compliant or metamorphopsia following PRK.

To report a case of bilateral cytomegalovirus (CMV) retinitis in an otherwise healthy infant.
A four-month-old, healthy, male infant was evaluated for visual inattention.
This full-term infant with a normal birth weight and an uneventful gestational period was referred with symptoms of visual inattention, fever, and agitation one week prior to admission. Ocular involvements were detected in the form of bilateral pan uveitis with diffuse bilateral retinitis and vasculitis with hemorrhage in the peripheral retina and posterior pole. CMV DNA was detected in the patient''s ocular sample and cerebrospinal fluid by polymerase chain reaction (PCR). He was treated with intravitreal and systemic ganciclovir. Unfortunately, the infant died because of CMV encephalitis. Therefore, bilateral CMV retinitis (CMVR), which was probably transmitted from the mother, was diagnosed in this immunocompetent infant.
The present case highlights the possibility of CMVR in immunocompetent infant associated with systemic CMV infection, even during the postnatal period. Therefore, a high index of clinical suspicion and prompt treatment may be life-saving in similar cases.

Blockage of the interleukin 1 (IL-1) signaling pathway has been proposed for treatment of inflammatory disorders like those affecting the retina and its adjacent tissue. Herein, we evaluated one of those inhibitory drugs, anakinra (Kineret®), based on its safety profile with emphasis on retinal function from an electrophysiological point of view.
Bovine retina preparations were perfused with two different concentrations of anakinra (1 mg/ml and 2 mg/ml). An electroretinogram (ERG) was recorded and b-wave recovery assessed.
Exposure to anakinra at a concentration of 1 mg/ml did not decrease the b-wave amplitude, whereas 2 mg/ml resulted in a significant reduction.
Based on these preliminary results, anakinra at a dose as low as 1 mg/ml could be regarded as safe for retinal function. However, dosages of 2 mg/ml and more do have toxic electrophysiological effects, at least for the short-term.